Contaminated erectile dysfunction drugs implicated in hypoglycemia outbreak

Illegal sexual enhancement drugs tainted with the diabetes drug glyburide have been linked to an outbreak of severe hypoglycemia in more than 100 Singaporeans, according to correspondence recently published in the New England Journal of Medicine (2009; 360:734-6).

Between Jan. 1 and May 26, 2008, a total of 150 nondiabetic patients with severe hypoglycemia were admitted to the five public hospitals in Singapore. All patients except one were male, ranging in age from 19 to 97 years. Seven remained comatose as a result of prolonged neuroglycopenia; four subsequently died.

Glyburide was detected in blood or urine samples of 127 of these patients (85%). On specific questioning, 45 patients (30%) admitted ingesting illegal sexual enhancement drugs before the onset of their hypoglycemia. Among these were counterfeit tadalafil and three herbal preparations for the purported treatment of erectile dysfunction, all containing glyburide in amounts ranging from 13 mg to 100 mg per tablet and sildenafil in amounts ranging from 0.5 mg to 110 mg per tablet.

Tests of certain batches of material manufactured before January 2008 found only sildenafil, suggesting recent contamination. Between January and June 2008, similar cases of hypoglycemia were reported in Hong Kong.

“We speculate that simultaneous contamination of several brands of drugs is consistent with a common manufacturing source,” wrote the report’s authors, led by Shih Ling Kao, MD, BS. “The drug packaging contained names of fictitious overseas factories, so it is not known whether there was deliberate or accidental contamination.”